The invention starts with a windshield wiper with a wiper arm in accordance with the pre-characterizing clause of claim 1.
Known windshield wipers feature a wiper arm, which sits on a wiper shaft. This shaft is driven by a wiper motor. A wiper blade is connected in an articulated manner to the free end of the wiper arm. As a rule, the wiper blade has a multi-unit supporting bracket system with a central bracket. Linked to this are subordinate brackets, several of which at least, having claws on their ends, hold a wiper strip. Inarticulate wiper blades are also known, which, instead of the supporting bracket system, have a resilient elastic supporting element that is fabricated of plastic perpendicular to the windshield. In order to improve the spring property it can feature at least one spring rail made of spring steel. In an unloaded state, the supporting element has a greater curvature than the vehicle window so that the wiper strip is applied to the vehicle window with appropriate pressure distribution under the application force by the wiper arm.
Inarticulate wiper blades are low-slung, something that is very favorable with regard to its behavior in terms of flow technology and noise development in the air stream wind. A windshield wiper with an inarticulate wiper blade, which is linked to a wiper arm via a so-called xe2x80x9csidelock system,xe2x80x9d is known from DE 199 24 662 A1. For this purpose, a pin on the free end of the wiper arm, which features a U-shaped profile that is open towards the vehicle window, is riveted laterally, transverse to its longitudinal direction and pointing towards the wiper blade. The pin is pivoted in a rest bore hole of a connecting part, which is permanently connected to the supporting element of the wiper blade.
A bridge is arranged parallel to the pin on the wiper arm offset in the longitudinal direction and the bridge is bent at its free end towards the side of the pin. In an assembly position, in which the wiper blade is held transverse to the longitudinal direction of the wiper arm, the pin can be put into the rest bore hole of the connecting part. If the wiper blade is subsequently rotated parallel to the longitudinal direction of the wiper arm, the bridge grips over the wiper blade and locks it with its bent end so that in an assembled state the wiper blade is guided onto the pin between the bent end of the bridge and the wiper arm. In the wiper blade""s operating position, the bridge dips into a corresponding groove of the connecting part and ends approximately flush with the upper side of the connecting part. For disassembly the wiper blade must be swiveled in the opposite direction until the bent end disengages and the wiper blade can be pulled from the pin.
Another sidelock system with a cylindrical adapter, which is used to compensate for different pin diameters, is known from U.S. Pat. No. 4,980,944 A1. The adapter has a rest bore hole, which is arranged eccentric to the outer contour of the adapter. In this arrangement, the eccentricity is selected in such a way that a continuous longitudinal slot is formed in the area of the circumference of the adapter. The adapter is pressed together for assembly and inserted into two openings of a U-shaped bracket of a wiper strip support. After being threaded in, the adapter reassumes its original form and with its circumference presses against the openings in the legs of the U-profile. A spring clip, which is arranged on the base surface of the U-profile and engages in the longitudinal slot, secures the adapter against twisting. Furthermore, it holds it in the axial direction by supporting itself on the lateral shoulders of the adapter. In a further assembly step, the pin fastened on the free end of the wiper arm can be put into the passage bore hole.
According to the invention, the wiper blade features a supporting bracket system with a center bracket that has an inset box, whose side walls are connected to one another via an articulated bolt and always feature at least one passage offset in the longitudinal direction to the articulated bolt. These types of wiper blades that are customary as such are used with wiper arms, which engage from above in the inset box with their hook-like end and encircle the articulated bolt with the use of an adapter or engage with two locking pins in two opposing passages.
According to the invention, a plastic adapter that is essentially U-shaped in cross-section and open at the bottom is inserted from above into the inset box, from whose covering wall collars project laterally beyond the side walls forming lateral guide surfaces in the area of the bridge. Adjacent to these are a bearing surface of the wiper arm and the bent end of the bridge in an assembled state and they guide the wiper blade in the axial direction of the pin. In addition, spring tongues are formed in opposing side walls of the adapter via slots on which tongues tubular bearing fittings are formed. These lock into passages and serve to pivot the wiper blade on the pin. The adapter supports itself with its collar on the side walls of the inset box so that it cannot rotate into the passages. In this process, the side walls each engage expediently in a groove which is provided in the collar. In addition, the adapter can be held by a clip, which is connected on the inside to the covering wall, preferably permanently, and in an assembled states encircles the articulated bolt with locking noses. This results in a very stable connection of the adapter to the wiper blade, thereby guaranteeing good guidance of the wiper blade.
Using the adapter in accordance with the invention, a wiper arm, whose free end is provided with a transverse pin for a sidelock system, can also be used for a wiper blade with a supporting bracket system. With respect to wind noise and flow resistance, the advantages that are connected with the flat, low construction of the sidelock system can be achieved with simple means also in the case of wiper blades with a supporting bracket system. In addition, the parts of the wiper arm and the wiper blade, which are normally fabricated of metal, namely sheet steel, can be isolated from one another by the adapter made of plastic so that movement noise and wear are minimized. In doing so, the shape and dimensions of the wiper arm and the wiper blade are advantageously retained so that no structural modifications or new tools are required to fabricate the components.
The adapter is inserted from above into the inset box, whereby the side walls of the adapter are adjacent to the insides of the inset box. Guide ribs are arranged on the outsides of the side walls in order to obtain defined contact surfaces in the area of the ends. These ribs are supported by a box-shaped hollow profile, which is formed by the front walls, parts of the side walls and the intermediate walls that run parallel to the front walls, and produces a rigid support. The parts of the side walls, which encircle the elastically flexible spring tongues with the bearing fittings, are separated from the hollow profiles by notches or recesses so that the bearing fittings can easily lock into the passages.
The adapter is expediently manufactured of a plastic, whereby all molded elements can be advantageously formed with the required precision during the injection process. In addition, as a rule plastic has good sliding properties, which are important in the case of the adapter according to the invention in the tubular bearing fittings since the pin of the wiper arm is pivoted here. Moreover, an intermediate adapter fabricated of plastic prevents undesired contact between the metal surfaces of the wiper arm and the wiper blade.